CN220770140U - Mechanical sealing structure - Google Patents

Abstract

The utility model discloses a mechanical sealing structure, which comprises a first stationary ring connected to a mounting flange and an elastic sleeve connected to a main shaft, wherein one side of the first stationary ring is connected with a second stationary ring, and one end of the second stationary ring facing the first stationary ring is provided with a mounting cavity; the elastic sleeve comprises a first straight cylinder part, a variable-diameter cylinder part and a second straight cylinder part which are integrally formed, wherein the diameter of the variable-diameter cylinder part gradually increases to the maximum value along the axial direction and then gradually decreases; the outer circumferences of the first straight cylinder part and the second straight cylinder part are respectively provided with a first moving ring and a second moving ring in a sliding way along the axial direction; one end of the first moving ring along the axial direction is abutted against the first stationary ring, one end of the second moving ring along the axial direction is abutted against the side wall of the mounting cavity, and the inner peripheral surfaces of the mutually facing ends of the first moving ring and the second moving ring are respectively provided with a first concave spherical surface and a second concave spherical surface which are matched with the reducing cylinder part; and a pressurizing hole is formed on the second stationary ring in a penetrating way. The utility model can seal the main shaft and the mounting flange with poor verticality between the axis of the main shaft and the mounting flange.

Description

Mechanical sealing structure

Technical Field

The utility model relates to the technical field of mechanical sealing, in particular to a mechanical sealing structure.

Background

The mechanical sealing device is a shaft sealing device of rotary machinery, is used for sealing and connecting a coaxially sleeved main shaft and a mounting flange, and is widely applied to equipment such as a mixer and the like. The main shaft of the mixer is horizontal (horizontally arranged), the sealing position of the main shaft and the mounting flange is covered by powder, and the sealing difficulty is high; most of the prior mechanical sealing devices for mixers have higher requirements on the verticality of the axis of the main shaft and the mounting flange when being mounted, and only the axis of the main shaft and the mounting flange have higher verticality, so that the main shaft and the mounting flange can be well sealed.

Disclosure of Invention

Therefore, the technical problem to be solved by the utility model is to overcome the defect that the prior mechanical sealing device requires high perpendicularity between the axis of the main shaft and the mounting flange during sealing assembly, thereby providing a mechanical sealing structure.

According to the utility model, a mechanical sealing structure is provided, and is connected between a main shaft and a mounting flange, and the mechanical sealing structure comprises:

the first stationary ring is used for being mounted on the mounting flange;

the second stationary ring is arranged on the first stationary ring in a butt joint manner, and an installation cavity is formed in one end, facing the first stationary ring, of the second stationary ring;

the elastic sleeve is used for being sleeved on the main shaft in an interference mode and comprises a first straight cylinder part, a variable-diameter cylinder part and a second straight cylinder part which are integrally formed, and the first straight cylinder part and the second straight cylinder part are respectively arranged at two ends of the variable-diameter cylinder part along the axial direction; the first straight cylinder part is arranged at one end of the variable-diameter cylinder part, which faces the first stationary ring; the diameter of the diameter-variable cylinder part gradually increases to the maximum value along the axial direction and then gradually decreases; the outer peripheral surfaces of one ends of the first straight cylinder part and the second straight cylinder part, which are away from each other, are respectively provided with a first lug and a second lug in a protruding mode, and the first lug and the second lug are both arranged in parallel to the axial direction;

the first moving ring is axially arranged outside the outer periphery of the first cylinder part, and a first chute matched with the first lug is arranged on the inner periphery of the first moving ring; one end of the first movable ring in the axial direction is abutted against the side wall of the first stationary ring, which is away from the mounting flange, and the inner peripheral surface of the other end in the axial direction is provided with a first concave spherical surface matched with the reducing cylinder part;

the second moving ring is axially arranged outside the outer periphery of the second straight cylinder part, and a second sliding groove matched with the second convex block is formed in the inner periphery of the second moving ring; one end of the second movable ring in the axial direction is abutted against the side wall of the mounting cavity, and the inner peripheral surface of the other end in the axial direction is provided with a second concave spherical surface matched with the reducing cylinder part;

the pressurizing hole penetrates through the second stationary ring along the radial direction of the second stationary ring, and the air outlet end of the pressurizing hole is positioned between the first movable ring and the second movable ring and is used for inflating and pressurizing the mounting cavity.

According to the mechanical sealing structure, at least the following technical effects are achieved:

1. the diameter of the diameter-changing cylinder part is gradually increased to the maximum value along the axial direction and then gradually reduced, so that the maximum diameter of the diameter-changing cylinder part is positioned in the middle of the diameter-changing cylinder part, the first concave spherical surface at one end of the first moving ring along the axial direction is matched with the outer circumferential surface of the diameter-changing cylinder part in a mode similar to a joint bearing, the other end of the first moving ring is abutted against the side wall of the first stationary ring, which is away from the mounting flange, and can rotate relatively, the second concave spherical surface at one end of the second moving ring along the axial direction is matched with the outer circumferential surface of the diameter-changing cylinder part in a mode similar to a joint bearing, and the other end of the second moving ring is abutted against the surrounding wall of the mounting cavity and can rotate relatively, and then the maximum diameter of the diameter-changing cylinder part limits the moving trend of the first moving ring and the second moving towards each other along the axial direction, so that the abutting sealing effect of the side wall of the first moving ring and the mounting flange is ensured in the process of the first moving ring and the main shaft together with the elastic sleeve and the main shaft.

2. The first concave spherical surface at one end of the first moving ring along the axial direction is matched with the outer peripheral surface of the variable-diameter cylinder part in a manner similar to a joint bearing, and the second concave spherical surface at one end of the second moving ring along the axial direction is matched with the outer peripheral surface of the variable-diameter cylinder part in a manner similar to a joint bearing; when the main shaft is deflected and swung to form a certain included angle with the axial direction, the installation cavity is inflated and pressurized through the pressurizing hole, and in the pressurizing process, the variable-diameter cylinder part can be deformed by adopting elastic materials, so that the first movable ring can deform and swing relatively to be parallel to the first stationary ring under the action force generated by pressurization, and the first movable ring is matched with the sliding connection relation of the first sliding chute and the first convex block to enable the first movable ring which is regulated to be parallel to the first stationary ring to move towards the direction close to the first stationary ring under the action force generated by pressurization, so that the first movable ring is ensured to be in contact with the first stationary ring to achieve a sealed state; meanwhile, the second movable ring can deform the second concave spherical extrusion diameter-changing cylinder part under the action force generated by pressurization to swing relatively to be parallel to the second stationary ring, and the second movable ring which is regulated to be parallel to the second stationary ring moves in the direction away from the first stationary ring under the action force generated by pressurization by matching with the sliding connection relation of the second sliding groove and the second convex block, so that the contact between the second movable ring and the surrounding wall of the mounting cavity is ensured to reach a sealed state; therefore, when the verticality between the axis of the main shaft and the mounting flange is poor or the main shaft swings and deviates in the using process, the mechanical sealing structure can still well seal the main shaft and the mounting flange; the method can reduce the perpendicularity requirement of the axis of the main shaft and the mounting flange, reduce the machining cost of the main shaft, allow the main shaft to swing in a certain range in a shifting manner on the basis of sealing, and improve the bending moment resistance of the main shaft.

3. Because the first lug and the second lug are made of elastic materials, the inertial impact on the first moving ring and the second moving ring when the main shaft starts to rotate and stops rotating can be eliminated, and impact and hard injury on the first moving ring and the second moving ring are avoided.

Preferably, a first sealing ring is arranged between the first concave spherical surface and the outer peripheral surface of the reducing cylinder part; and a second sealing ring is arranged between the second concave spherical surface and the outer peripheral surface of the reducing cylinder part.

Preferably, a circle of first mounting ring grooves are concavely arranged on the first concave spherical surface, and the first sealing rings are embedded in the first mounting ring grooves; the second concave spherical surface is concavely provided with a circle of second installation ring groove, and the second sealing ring is embedded into the second installation ring groove.

Preferably, the first moving ring and the second moving ring are provided as the same moving ring, and the diameter-changing cylindrical portion is arranged symmetrically with respect to a center of the diameter-changing cylindrical portion in the axial direction.

Preferably, the first protrusions are provided in two, and the two first protrusions are symmetrically arranged along the radial direction of the first straight tube portion.

Preferably, the number of the second protrusions is two, and the two second protrusions are symmetrically arranged along the radial direction of the second straight barrel portion.

Preferably, the device further comprises a first fool-proof gap, wherein the first fool-proof gap is arranged between the inner peripheral surface of the first stationary ring and the outer peripheral surface of the main shaft.

Preferably, the device further comprises a second fool-proof gap, wherein the second fool-proof gap is arranged between the inner hole wall of the second stationary ring and the outer peripheral surface of the main shaft.

Preferably, two of the supercharging holes are arranged at equal intervals along the circumferential direction.

Preferably, the first moving ring and the second moving ring are made of polytetrafluoroethylene.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic perspective view of a mechanical seal structure of the present embodiment connected between a mounting flange and a spindle;

FIG. 2 is a schematic diagram of the front view structure of FIG. 1;

FIG. 3 is a schematic cross-sectional view of the structure at A-A in FIG. 2;

FIG. 4 is an enlarged schematic view at B in FIG. 3;

FIG. 5 is a schematic view of the elastic sleeve in the present embodiment;

FIG. 6 is a schematic structural view of the present embodiment connected between the mounting flange and the spindle with the spindle having an offset wobble angle with respect to the axial direction;

fig. 7 is an enlarged schematic view at C in fig. 6.

Reference numerals illustrate:

1-a main shaft;

2-mounting a flange;

31-first stationary ring, 32-second stationary ring, 321-mounting cavity, 322-pressurizing hole, 33-elastic sleeve, 331-first straight tube portion, 332-reducing tube portion, 333-second straight tube portion, 334-first bump, 335-second bump, 34-first movable ring, 341-first concave sphere, 342-first sealing ring, 343-first mounting ring groove, 35-second movable ring, 351-second concave sphere, 352-second sealing ring, 353-second mounting ring groove, 36-first fool-proof gap, 37-second fool-proof gap, 38-threaded hole.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

As shown in fig. 1 to 7, a mechanical seal structure provided in this embodiment is shown, and is applied between a main shaft 1 and a mounting flange 2 of a mixer, wherein the main shaft 1 is horizontal; the mechanical sealing structure comprises a first static ring 31 and an elastic sleeve 33, wherein the first static ring 31 is arranged on the mounting flange 2, the elastic sleeve 33 is used for being in interference sleeve connection with the main shaft 1, one side, away from the mounting flange 2, of the first static ring 31 is provided with a second static ring 32 in an abutting connection mode, and one end, facing the first static ring 31, of the second static ring 32 is provided with a mounting cavity 321; the elastic sleeve 33 includes a first straight tube portion 331, a variable diameter tube portion 332, and a second straight tube portion 333 that are integrally formed, wherein the first straight tube portion 331 and the second straight tube portion 333 are disposed at two ends of the variable diameter tube portion 332 in the axial direction; the first cylindrical portion 331 is disposed at an end of the diameter-variable cylindrical portion 332 facing the first stationary ring 31; the diameter of the diameter-variable cylinder 332 gradually increases to a maximum value in the axial direction and then gradually decreases; the outer peripheral surfaces of the ends of the first straight tube portion 331 and the second straight tube portion 333 facing away from each other are respectively provided with a first protruding block 334 and a second protruding block 335, and the first protruding block 334 and the second protruding block 335 are both arranged parallel to the axial direction; a first moving ring 34 is axially arranged on the outer periphery of the first cylindrical part 331, and a first chute matched with the first projection 334 is arranged on the inner periphery of the first moving ring 34; one end of the first movable ring 34 in the axial direction is abutted against the side wall of the first stationary ring 31, which is away from the mounting flange 2, and the inner circumferential surface of the other end in the axial direction is provided as a first concave spherical surface 341 matched with the small diameter end of the variable diameter cylinder 332; a second moving ring 35 is axially arranged on the outer periphery of the second straight barrel 333, and a second sliding groove matched with the second protruding block 335 is arranged on the inner periphery of the second moving ring 35; one end of the second moving ring 35 in the axial direction is abutted against the side wall of the mounting cavity 321, and the inner circumferential surface of the other end in the axial direction is provided with a second concave spherical surface 351 matched with the small diameter end of the diameter-variable cylinder 332; the middle part of the installation cavity 321 is radially penetrated and formed with a pressurizing hole 322, and an air outlet end of the pressurizing hole 322 is positioned between the first movable ring 34 and the second movable ring 35 and is used for inflating and pressurizing the installation cavity 321. It will be appreciated that the axial direction described in this embodiment refers to the axial direction in fig. 3.

Compared with the prior art, in the mechanical seal structure of this embodiment, the diameter of the diameter-variable cylinder portion 332 is gradually reduced after being gradually increased to the maximum value along the axial direction by integrally forming the diameter-variable cylinder portion 332 between the first straight cylinder portion 331 and the second straight cylinder portion 333, so that the maximum diameter of the diameter-variable cylinder portion 332 is located in the middle of the diameter-variable cylinder portion 332, the first concave spherical surface 341 at one end of the first moving ring 34 along the axial direction is matched with the outer circumferential surface of the diameter-variable cylinder portion 332 in a manner similar to a joint bearing, and the other end of the first moving ring 34 along the axial direction is abutted against the side wall of the first stationary ring 31, which is away from the mounting flange 2, and can rotate relatively, and meanwhile, the second concave spherical surface 351 at one end of the second moving ring 35 along the axial direction is matched with the outer circumferential surface of the diameter-variable cylinder portion 332 in a manner similar to a joint bearing, and after the other end of the moving ring 34 along the axial direction is abutted against the mounting cavity 321 and can rotate relatively, the trend that the first moving ring 34 and the second moving ring 35 move relatively along the axial direction is limited, so that the first moving ring 34 and the second moving ring 35 are always kept close to each other along the axial direction, and the first moving ring 33 and the first moving ring 1 are always kept in the axial direction, and the sealing effect is ensured, and the sealing effect is realized, and sealing effect is realized, that sealing the side is achieved by the mounting the moving ring and the main body and the main ring and the main body 1.

The mechanical seal structure of the present embodiment is also formed by fitting the first concave spherical surface 341 of the first movable ring 34 at one end in the axial direction with the outer peripheral surface of the variable-diameter cylindrical portion 332 in a manner resembling a "knuckle bearing", and fitting the second concave spherical surface 351 of the second movable ring 35 at one end in the axial direction with the outer peripheral surface of the variable-diameter cylindrical portion 332 in a manner resembling a "knuckle bearing"; when the spindle 1 swings in a shifting manner and forms a certain angle with the axial direction (as shown in fig. 6), the installation cavity 321 is inflated and pressurized through the pressurizing hole 322 (namely, the space of a sealed part of the installation cavity 321 surrounded by the first movable ring 34, the second movable ring 35, the elastic sleeve 33 and the first static ring 31 is continuously inflated and pressurized through the pressurizing hole 322), in the pressurizing process, because the reducing cylinder part 332 is made of elastic materials and can be deformed, the first movable ring 34 can enable the first concave spherical surface 341 to squeeze the reducing cylinder part 332 to deform under the action force generated by pressurization to generate relative swing to be parallel to the first static ring 31, and the sliding connection relation between the first sliding groove and the first convex block 334 is matched to enable the first movable ring 34 which is regulated to be parallel to the first static ring 31 to move towards the direction close to the first static ring 31 under the action force generated by pressurization, so that the first movable ring 34 is ensured to be in contact with the first static ring 31 to achieve a sealed state; meanwhile, the second movable ring 35 can deform the variable diameter cylinder 332 extruded by the second concave spherical surface 351 under the action of the pressure boost to swing relatively to be parallel to the second stationary ring 32, and the second movable ring 35 which is regulated to be parallel to the second stationary ring 32 moves away from the first stationary ring 31 under the action of the pressure boost by matching with the sliding connection relation of the second sliding groove and the second convex block 335, so that the contact between the second movable ring 35 and the surrounding wall of the mounting cavity 321 is ensured to reach a sealed state; and because the air pressure in the space of the sealed part mounting cavity 321 is equal everywhere, the side walls of the first movable ring 34 and the first static ring 31 and the surrounding walls of the second movable ring 35 and the mounting cavity 321 are all in full contact, no local gap exists, and the sealing reliability is ensured; so as to ensure that the mechanical sealing structure of the embodiment can still perform good sealing on the main shaft 1 and the mounting flange 2 when the verticality between the axis of the main shaft 1 and the mounting flange 2 is poor or the main shaft 1 generates offset swing in the use process; the axial line of the main shaft 1 and the perpendicularity requirement of the mounting flange 2 can be reduced, the machining cost of the main shaft 1 is reduced, the main shaft 1 can be allowed to swing and adjust within a certain range on the basis of sealing, and the bending moment resistance of the main shaft 1 is improved.

Meanwhile, because the first protruding block 334 and the second protruding block 335 are made of elastic materials, inertial impact on the first moving ring 34 and the second moving ring 35 when the spindle 1 starts rotating and stops rotating can be eliminated, and impact and hard injury on the first moving ring 34 and the second moving ring 35 are avoided.

It should be noted that, in the working process of the mixer, that is, in the whole process of starting the rotation of the spindle 1, the inflation device always charges air and pressurizes the space of the sealed part of the mounting cavity 321 surrounded by the first movable ring 34, the second movable ring 35, the elastic sleeve 33 and the first static ring 31 through the pressurizing holes 322, so that when the spindle 1 shakes or forms a certain included angle with the axial direction in the use process, the position of the first movable ring 34 and the second movable ring 35 can be automatically adjusted by the acting force generated by pressurization, the position of the acting force is abutted against the side wall of the first static ring 31 and the surrounding wall of the mounting cavity 321 again, the end face seal is always maintained, the spindle 1 can swing within a certain range on the basis of sealing, the bending moment resistance of the spindle 1 can be improved, and the requirement of the perpendicularity between the axis of the spindle 1 and the mounting flange 2 can be reduced.

It should be further noted that, because the air outlet end of the pressurizing hole 322 is located between the first moving ring 34 and the second moving ring 35, during the continuous inflation and pressurization process in the space of the sealed part of the installation cavity 321 enclosed by the pressurizing hole 322, which is defined by the first moving ring 34, the second moving ring 35, the elastic sleeve 33 and the first stationary ring 31, the air inflated from the air outlet end of the pressurizing hole 322 diffuses from the middle part of the space of the sealed part of the installation cavity 321 to two ends, so that the acting force generated by pressurization ensures that the first moving ring 34 and the second moving ring 35 move along the direction deviating from each other, and further ensures the sealing reliability.

To ensure that when at least one of the first moving ring 34, the second moving ring 35, or the elastic sleeve 33 installed in the installation cavity 321 is damaged to make service impossible, the second stationary ring 32 may be detached from the first stationary ring 31 to perform service replacement of the components installed in the installation cavity 321; as shown in fig. 1, 3 and 4, specifically, at least two threaded holes 38 are formed at corresponding positions on the first stationary ring 31 and the second stationary ring 32 in a penetrating manner along the axial direction, and when assembled, fastening bolts are screwed into the threaded holes 38 of the second stationary ring 32 and the first stationary ring 31 in sequence.

As shown in fig. 3, 4, 6 and 7, in some embodiments of the present utility model, a first sealing ring 342 is disposed between the first concave spherical surface 341 and the outer circumferential surface of the reducing cylinder portion 332; a second seal ring 352 is provided between the second concave spherical surface 351 and the outer peripheral surface of the diameter-variable cylinder 332. The first seal ring 342 and the second seal ring 352 can improve the sealing effect of the junction between the first concave spherical surface 341 and the diameter-variable cylindrical portion 332 and the junction between the second concave spherical surface 351 and the diameter-variable cylindrical portion 332, and can improve the sealing performance of the sealed space of the partial installation cavity 321 surrounded by the first movable ring 34, the second movable ring 35, the elastic sleeve 33 and the first stationary ring 31, so as to ensure the inflating and pressurizing effect of the pressurizing hole 322 on the sealed space of the partial installation cavity 321, thereby ensuring that the positions of the first movable ring 34 and the second movable ring 35 are automatically adjusted according to the offset swinging condition of the main shaft 1 to always be in abutting connection with the side wall of the first stationary ring 31 and the surrounding wall of the installation cavity 321 to keep the end face seal.

As shown in fig. 7, in some embodiments of the present utility model, a circle of first mounting ring grooves 343 is concavely formed on the first concave spherical surface 341, and the first sealing ring 342 is embedded in the first mounting ring grooves 343; the second concave spherical surface 351 is concavely provided with a circle of second installation ring groove 353, and the second sealing ring 352 is embedded in the second installation ring groove 353. The first installation annular groove 343 and the second installation annular groove 353 limit the positions of the first sealing ring 342 and the second sealing ring 352 respectively, so that the first sealing ring 342 is prevented from generating axial displacement relative to the first concave spherical surface 341 and the second sealing ring 352 is prevented from generating axial displacement relative to the second concave spherical surface 351, and accordingly, in the process of adjusting the movement of the first movable ring 34 and the second movable ring 35 to be always in contact with the side wall of the first static ring 31 and the surrounding wall of the installation cavity 321 to keep end face sealing under the action of the pressurizing force, the connection part of the first concave spherical surface 341 and the variable diameter cylinder 332 and the connection part of the second concave spherical surface 351 and the variable diameter cylinder 332 always keep good sealing effect.

In order to simplify the difficulty in assembling the first and second movable rings 34 and 35 with the elastic sleeve 33, as shown in fig. 4 and 5, in some embodiments of the present utility model, the first and second movable rings 34 and 35 are provided as identical movable rings, and the variable diameter cylindrical portion 332 is symmetrically arranged about the center of the variable diameter cylindrical portion 332 in the axial direction. In the assembly process, an assembler cannot distinguish the first movable ring 34 from the second movable ring 35 additionally, so that the assembly efficiency is improved.

As shown in fig. 3 to 5, in some embodiments of the present utility model, the first protrusions 334 are provided in two, and the two first protrusions 334 are symmetrically arranged along the radial direction of the first straight tube portion 331. Two first lugs 334 symmetrically arranged along the radial direction of the first straight barrel 331 can enable the first movable ring 34 to move more accurately towards the direction close to the first stationary ring 31 under the driving of the acting force generated by pressurization, ensure that when the main shaft 1 shakes or the offset swing and the axial direction form a certain included angle in the use process, the position of the first movable ring 34 can be adjusted more accurately automatically by the acting force generated by the pressurization, the end face is always kept to be sealed with the side wall of the first stationary ring 31 in a butt joint mode, and the sealing reliability is ensured.

As shown in fig. 3 to 5, in some embodiments of the present utility model, the second protrusions 335 are provided in two, and the two second protrusions 335 are symmetrically arranged along the radial direction of the second straight cylinder 333. Two second convex blocks 335 which are symmetrically arranged along the radial direction of the second straight barrel 333 can enable the second movable ring 35 to move more accurately towards the direction deviating from the first movable ring 34 under the drive of the acting force generated by pressurization, so that when the main shaft 1 shakes or a certain included angle is formed between the offset swing and the axial direction in the use process, the acting force generated by the pressurization can more accurately automatically adjust the position of the second movable ring 35 to be in abutting connection with the surrounding wall of the mounting cavity 321 all the time, and the sealing reliability is ensured.

As shown in fig. 3 and 4, in some embodiments of the present utility model, the mechanical seal structure further includes a first fool-proof gap 36, where the first fool-proof gap 36 is disposed between the inner peripheral surface of the first stationary ring 31 and the outer peripheral surface of the main shaft 1. The first foolproof gap 36 can play a role of avoiding abrasion caused by contact with the inner peripheral surface of the first stationary ring 31 when the main shaft 1 shakes or has a certain included angle with the axial direction in the use process, and the service life of the mechanical seal structure of the embodiment is prolonged.

As shown in fig. 3 and 4, in some embodiments of the present utility model, the mechanical seal structure further includes a second fool-proof gap 37, where the second fool-proof gap 37 is disposed between the inner hole wall of the second stationary ring 32 and the outer peripheral surface of the main shaft 1. The second fool-proof gap 37 can play a role in avoiding abrasion caused by contact with the inner hole wall of the second stationary ring 32 when the main shaft 1 shakes or forms a certain included angle with the axial direction in the use process, and the service life of the mechanical sealing structure of the embodiment is prolonged.

As shown in fig. 6 and 7, in some embodiments of the present utility model, two of the pressurizing holes 322 are provided, and the two pressurizing holes 322 are equally spaced in the circumferential direction. Through two supercharging holes 322 which are symmetrically arranged about the axial direction, the space of a sealed part of the installation cavity 321 which is surrounded by the first movable ring 34, the second movable ring 35, the elastic sleeve 33 and the first static ring 31 can be continuously inflated and supercharged, so that when the main shaft 1 shakes or a certain included angle is formed between offset swing and the axial direction in the use process, the position of the first movable ring 34 and the second movable ring 35 can be automatically adjusted by acting force generated by supercharging, and the position of the first movable ring 34 and the second movable ring 35 is abutted against the side wall of the first static ring 31 and the surrounding wall of the installation cavity 321 to always keep end face sealing, the main shaft 1 can swing within a certain range on the basis of sealing, and the bending moment resistance of the main shaft is improved. It should be noted that, in a specific application, the number of the pressurizing holes 322 may be reasonably increased or decreased according to the size of the space of the sealed part of the installation cavity 321 enclosed by the first moving ring 34, the second moving ring 35, the elastic sleeve 33 and the first static ring 31, for example, in other embodiments, one, three, four, etc. of the pressurizing holes 322 are provided.

In some embodiments of the present utility model, the first moving ring 34 and the second moving ring 35 are made of polytetrafluoroethylene. The first movable ring 34 and the second movable ring 35 which are made of polytetrafluoroethylene have high lubricity, ensure that the first movable ring 34 and the second movable ring 35 rotate relative to the side wall of the first static ring 31 and the surrounding wall of the mounting cavity 321 respectively to perform dynamic sealing, and are not easy to wear, so that the service life of the mechanical sealing structure of the embodiment is prolonged.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims (10)

1. A mechanical seal structure, applied between a spindle (1) and a mounting flange (2), characterized in that it comprises:

a first stationary ring (31) for mounting on the mounting flange (2);

the second stationary ring (32) is arranged on the first stationary ring (31) in an abutting mode, and an installation cavity (321) is formed in one end, facing the first stationary ring (31), of the second stationary ring (32);

the elastic sleeve (33) is used for being sleeved on the main shaft (1) in an interference manner, the elastic sleeve (33) comprises a first straight cylinder part (331), a variable-diameter cylinder part (332) and a second straight cylinder part (333) which are integrally formed, and the first straight cylinder part (331) and the second straight cylinder part (333) are respectively arranged at two ends of the variable-diameter cylinder part (332) along the axial direction; the first straight tube part (331) is arranged at one end of the variable-diameter tube part (332) facing the first stationary ring (31); the diameter of the diameter-changing cylinder part (332) gradually increases to the maximum value along the axial direction and then gradually decreases; the outer peripheral surfaces of one ends of the first straight tube part (331) and the second straight tube part (333) which are away from each other are respectively provided with a first lug (334) and a second lug (335) in a protruding mode, and the first lug (334) and the second lug (335) are arranged in parallel to the axial direction;

a first moving ring (34) axially arranged on the outer periphery of the first cylindrical part (331), wherein a first sliding groove matched with the first protruding block (334) is arranged on the inner periphery of the first moving ring (34); one end of the first movable ring (34) in the axial direction is abutted against the side wall of the first stationary ring (31) deviating from the mounting flange (2), and the inner circumferential surface of the other end in the axial direction is provided with a first concave spherical surface (341) matched with the reducing cylinder part (332);

a second moving ring (35) axially arranged outside the outer periphery of the second straight tube part (333), wherein a second sliding groove matched with the second protruding block (335) is arranged on the inner periphery of the second moving ring (35); one end of the second movable ring (35) in the axial direction is abutted against the side wall of the mounting cavity (321), and the inner peripheral surface of the other end in the axial direction is provided with a second concave spherical surface (351) matched with the variable-diameter cylinder part (332);

the pressurizing hole (322) penetrates through the second stationary ring (32) along the radial direction of the second stationary ring (32), and the air outlet end of the pressurizing hole (322) is positioned between the first movable ring (34) and the second movable ring (35) and is used for inflating and pressurizing the mounting cavity (321).

2. The mechanical seal structure according to claim 1, wherein a first seal ring (342) is provided between the first concave spherical surface (341) and the outer peripheral surface of the diameter-variable cylindrical portion (332); a second seal ring (352) is provided between the second concave spherical surface (351) and the outer peripheral surface of the diameter-variable cylinder (332).

3. The mechanical seal structure according to claim 2, wherein a circle of first installation ring grooves (343) are concavely formed on the first concave spherical surface (341), and the first sealing ring (342) is embedded in the first installation ring grooves (343); the second concave spherical surface (351) is concavely provided with a circle of second installation ring grooves (353), and the second sealing ring (352) is embedded into the second installation ring grooves (353).

4. A mechanical seal according to any one of claims 1 to 3, wherein the first and second movable rings (34, 35) are provided as identical movable rings, and the variable-diameter cylindrical portion (332) is arranged symmetrically with respect to the center of the variable-diameter cylindrical portion (332) in the axial direction.

5. A mechanical seal according to claim 1, wherein said first projections (334) are provided in two, and wherein said two first projections (334) are symmetrically arranged along a radial direction of said first straight tube portion (331).

6. A mechanical seal according to claim 1 or 5, wherein the second protrusions (335) are provided in two, the two second protrusions (335) being symmetrically arranged along the radial direction of the second straight tube portion (333).

7. The mechanical seal structure according to claim 1, further comprising a first foolproof gap (36), wherein the first foolproof gap (36) is disposed between an inner peripheral surface of the first stationary ring (31) and an outer peripheral surface of the main shaft (1).

8. A mechanical seal according to claim 1 or 7, further comprising a second foolproof gap (37), said second foolproof gap (37) being arranged between an inner hole wall of said second stationary ring (32) and an outer peripheral surface of the main shaft (1).

9. A mechanical seal according to claim 1, wherein two of said pressurizing holes (322) are provided, and wherein two of said pressurizing holes (322) are arranged at equal intervals in a circumferential direction.

10. A mechanical seal according to claim 1, wherein the first ring (34) and the second ring (35) are made of polytetrafluoroethylene.